Genesys PHO in Flint, Mich., is one of 32 ACOs participating in the Pioneer ACO Model initiative administered by the CMS. Genesys PHO' experience suggests that successful ACOs will invest physicians with decision power and focus on strengthening the physician-patient relationship, restoring patients' trust in physicians, and allocating the right human resources to the effort. Organizations that are considering an ACO strategy should evaluate the risk structures of their proposed contracts and their provider groups' willingness to accept the contractual level of risk.